A trading system isn't needed...

There really isn't mush to trade anyway.

Classic has already tried to stop the hat chasers by that no gif 1k's rule.
so why would they want hat chasers to scam players for rare hats.

There are only a few things that would be worth trading anyways. Hats, Furniture and GST taunts...
Thats it.

I think that as soon as classic adds items such as weapons and an event coin system is when the trading system can be implemented.